Imaging System for Multi-Fiber Connector Inspection

ABSTRACT

A digital fiber optic connector imaging system that can automatically capture two or more images of the endface of a multifiber connector, wherein the captured images as a group have sufficient resolution and a sufficient FOV to be used to perform a manual or automatic pass-fail analysis of the endface of every fiber terminated by the connector under inspection. In one or more embodiments, the imaging system comprises an illumination source that can operate at two or more wavelengths, one wavelength at a time, and a FOV-shifting component that includes one or more, fixed dichroic mirrors and one additional dichroic or broadband mirror. In other embodiments, the imaging system comprises a single-wavelength illumination source, an image beam splitter, and two or more image sensors located on two image planes.

BACKGROUND Field of the Invention

This disclosure generally relates to fiber optic connector inspection,and more particularly to microscopes used to inspect multifiberconnectors.

Background of the Invention

Fiber optic links are key elements in many local and wide area digitalbroadband networks. However, even micron-sized dust particles or defectsin the endface of a fiber optic connector can cause a link to fail. Thustechnicians who install or maintain fiber optic equipment or cables inthe field, as well as associates who perform assembly or qualityassurance functions at facilities that manufacture fiber optic equipmentor cable assemblies, are normally required to inspect the endface ofevery fiber optic connector before it is mated with another connector.

A wide range of single-fiber and multiple-fiber connector types are inuse today. A popular multiple-fiber connector type called “MPO” isavailable in versions that can terminate from 12 to 72 individualoptical fibers. For example, the endface of an MPO 32 connector includesthe endfaces of 32 fibers grouped in two rows of 16 fibers each, whilethe endface of an MPO 72 connector includes the endfaces of 72 fibers,grouped in six rows of 12 fibers each.

Multifiber adapters for single-fiber connector inspection microscopesare disclosed in U.S. Pat. No. 8,104,976 (Zhou et. al.), U.S. Pat. No.7,239,788 (Villeneuve), and U.S. Pat. No. 6,879,439 (Cassady). However,these systems must be operated manually and therefore may be slow ordifficult to use.

An imaging system that could be used to implement adapters that wouldallow compatible single-fiber microscopes to automatically inspectmultiple-fiber connectors, or to implement automatic, multiple-fiberinspection microscopes, is disclosed in U.S. Pat. Appl. 20150092043(BARIBAULT). However, the preferred embodiment of this system includesone or more servomotor-controlled mirrors, and thus may not meet thereliability, drop-test, or vibration tolerance requirements of someusers.

It is also possible to imagine a fiber optic connector microscope ableto capture single images that encompass all fibers in the endface of anyconnector in a specified set of multiple-fiber connectors. Such amicroscope could be fast and rugged. But its implementation wouldrequire the use of a very large image sensor. For example, as shown inFIG. 1, if we assume a specified set of connectors that includes MPO 32and MPO 72 type connectors, and add some margin to account formechanical tolerances, then the total area on the endface underinspection which must be viewable by the microscope, or the minimummicroscope Field of View (FOV) 103, would be a rectangle with ahorizontal dimension (H) of 4.6 mm and a vertical dimension (V) of 2.1mm. If we further assume a sensor aspect ratio of 3:2, which is commonfor high pixel count, large format image sensors, then the FOV of eachimage captured by the sensor, or the sensor FOV, must also have a widthof 4.6 mm, as shown in FIG. 2. If we further assume a microscoperesolution requirement of 1 micron, and thus a pixel density requirementof about 2 pixels per micron, then the sensor would must have a total of4600 um×2 pixels/micron=9600 pixels in the horizontal dimension. Thusthe required sensor size in terms of pixels would equal [2/3][9600]² orabout 56 million pixels (Mp). Or if our goal is to match the resolutionof current art, single-fiber microscopes, or about 0.5 microns, then apixel density of 4 pixels per micron may be required. In this case theimage sensor would require over 200 million pixels.

Thus, there is a need in the art for an imaging system that may be usedto implement multiple-fiber connector inspection microscopes that arefree of the disadvantages mentioned above.

SUMMARY OF THE INVENTION

This description discloses multiple exemplary embodiments of an imagingsystem that can automatically capture multiple images of the endface ofa multiple-fiber connector, wherein the images together encompass theendfaces of all of the individual fibers terminated by the connector.One example embodiment includes a three-wavelength illumination source,a wavelength-controlled FOV shifter, and a single image sensor. TheFOV-shifter component further comprises two dichroic beam-splitters anda mirror disposed in front of the endface under inspection so that thecurrent illumination wavelength determines which endface section isvisible to the image sensor. Thus the image sensor will see the left,middle, or right section of the endface under inspection at any giventime, depending on which illumination wavelength is active. In thisembodiment the FOV of the objective lens and the pixel count of theimage sensor must be large enough to achieve an image FOV of only about⅓ of the total endface area.

In another embodiment, the single image sensor of the aforementionedembodiment is replaced by an image beam-splitter used to create twoimage planes, and two image sensors, wherein each image sensor isdisposed on a different image plane. This embodiment may be used toincrease microscope FOV without using a much more expensive image sensortype.

One drawback to the embodiments that include the wavelength-controlledFOV-shifter is that optical path length will be different for eachillumination wavelength, which reduces auto-focus range. Two additionalembodiments are provided to address this issue. The first includes anoptical path length equalizer component, which may be implemented withdichroic beam-splitters and mirrors. The second includes an imageseparator and one image sensor per wavelength, wherein the imageseparator comprises one or more dichroic beam-splitters, and wherein thedistance between each of these sensors and the wavelength separator isselected to achieve the same optical path length at each illuminationwavelength.

Another embodiment includes an objective lens with an FOV thatencompasses all individual fibers in the multiple-fiber connector underinspection, a single-wavelength illumination source, an imagebeam-splitter, and two or more image sensors, wherein the image beamsplitter is used to create two image planes, and the sensors aredisposed on these planes such that they capture images that encompassthe endfaces of all individual fibers terminated by the multiple-fiberconnector under inspection.

BRIEF DESCRIPTION OF DRAWINGS

The figures in this disclosure are not necessarily drawn to scale inorder to clearly show relationships between the components included inthe described systems. Also, the figures do not show the power,processor, driver, or other electronic circuits used to power and/orcontrol the illumination source, autofocus lens, and image sensors.

FIG. 1 (Prior Art) illustrates the minimum microscope FOV needed tocapture an image of the endface of all fibers terminated by an MPO 32 orMPO 72 type multiple-fiber connector.

FIG. 2 (Prior Art) illustrates the image FOV of a single, large imagesensor with a 3:2 aspect ratio relative to the example minimummicroscope FOV shown in FIG. 1.

FIG. 3 illustrates the FOV shifting component that includes two dichroicbeam-splitters and a mirror.

FIG. 4 illustrates the optical path length equalizer component thatincludes four dichroic beam-splitters and two mirrors.

FIG. 5 illustrates the wavelength separator component that includes twodichroic beam-splitters.

FIG. 6 illustrates the example three-wavelength, single-sensorembodiment.

FIG. 7 illustrates how the FOVs of the three images captured by theexample three-wavelength, single-sensor embodiment would cover theexample minimum microscope FOV.

FIG. 8 illustrates the example three-wavelength, single-sensorembodiment with an optical path length equalizer.

FIG. 9 illustrates the example three-wavelength, three-sensor embodimentin which the sensors are disposed to create the same optical path lengthat each wavelength.

FIG. 10 illustrates the example three-wavelength, two-sensor embodiment.

FIG. 11 illustrates how the FOVs of the six images captured by theexample three-wavelength, two-sensor embodiment would cover the exampleminimum microscope FOV.

FIG. 12 illustrates the example three-wavelength, two-sensor embodimentwith an optical patch length equalizer.

FIG. 13 illustrates the example single-wavelength, two-sensorembodiment.

FIG. 14 illustrates how the FOVs of the two images captured by theexample single-wavelength, two-sensor embodiment would cover the exampleminimum microscope FOV.

FIG. 15 illustrates an example single-wavelength, three-sensorembodiment.

FIG. 16 illustrates how the FOVs of the three images captured by theexample single-wavelength, three-sensor embodiment would cover theexample minimum microscope FOV.

LIST OF THE ELEMENTS USED IN THE SPECIFICATION AND DRAWINGS

-   101—Area on MPO 32 connector endface containing individual fiber    endfaces.-   102—Area on MPO 72 connector endface containing individual fiber    endfaces.-   103—An example minimum overall or aggregate image FOV for a    microscope designed to inspect a set of connectors that includes MPO    32 and MPO 72.-   104—X-width of minimum microscope FOV, in mm.-   105—Y-height of minimum microscope FOV, in mm.-   201—Image sensor (physical package).-   202—Active area of image sensor.-   203—H-sensor size in horizontal dimension, in terms of pixels.    Figure illustrates a sensor with a 3:2 aspect ratio in landscape    orientation.-   204—V-sensor size in vertical dimension, in terms of pixels. Figure    illustrates a sensor with a 3:2 aspect ratio in landscape    orientation.-   301—Image FOV for single large sensor (current art), FOV determined    by horizontal dimension.-   302—H1-single image FOV, horizontal dimension, in pixels.-   303—V1-single image FOV, vertical dimension, in pixels.-   400—Image FOV shifter for three wavelengths.-   401—Two-way light path with all three wavelengths.-   402—First reflecting surface, dichroic beam splitter, reflects λ1,    passes λ2 and λ3. Can be dielectric mirror with either band reflect    or short reflect characteristics.-   403—Two-way light path to center of FOV for λ1 in endface (object)    plane.-   404—Two-way light path with only λ2 and λ3.-   405—Second reflecting surface, dichroic beam splitter, reflects λ2,    passes λ3. Can be dielectric mirror with either band reflect or    short reflect characteristics.-   406—Two-way light path to center of FOV for λ2 in endface (object)    plane.-   407—Two-way light path with a-   408—Third reflecting surface, dichroic mirror, reflects λ3 and    passes λ2 and λ3. NOTES: Can be dichroic mirror with band reflect or    long reflect characteristics. Or, could be broadband dielectric    mirror. Or, could be metallic mirror. Need to show preferred    embodiment with NO either/or. So need to ask Peter what our    preferred embodiment is!-   409—Light path to center of FOV for λ3 in endface (object) plane.-   410—E1, distance between mirror for λ3 and mirror for λ1. And thus    the amount that the optical path at λ1 must be extended.-   411—E2, distance between mirror for λ3 and mirror for λ2. And thus    the amount that the optical path at λ2 must be extended.-   412—The endface plane, and therefore the object plane of the    microscope.-   500—Optical path length equalizer component for three wavelengths.-   501—Input optical path with all three wavelengths.-   502—Dichroic beam splitter, reflects λ1 and λ2, passes λ3.-   503—Transmitted optical path from dichroic beam-splitter 502 with a-   504—Dichroic beam splitter, passes a reflects λ1 and λ2.-   505—Output optical path with all three wavelengths.-   506—Reflected optical path from dichroic beam splitter 502 with λ1    and λ2.-   507—Dichroic beam splitter, reflects λ2, passes λ1.-   508—Reflected optical path from dichroic beam splitter 507.-   509—Dichroic beam splitter, reflects λ2, passes λ1.-   510—Optical path segment with λ1 and λ2.-   511—Optical path segment with λ1.-   512—Mirror, reflect λ1.-   513—Optical path segment with λ1.-   514—Mirror, reflects λ1.-   515—Optical path segment with λ1.-   516—Horizontal distance between left and right components. All    wavelengths travel this distance.-   517—Vertical distance between dichroic beam splitter 502 and    dichroic beam splitter 507, which should equal E2. This distance is    traveled by λ2.-   518—Vertical distance between dichroic beam splitter 502 and mirror    512, which should equal E1. This distance is traveled twice by λ1.-   600—Wavelength separator component for three wavelengths.-   601—Input optical path with all three wavelengths.-   602—Dichroic beam splitter, reflects λ1 and λ2, passes λ3.-   603—Optical path segment from dichroic beam splitter 602 to output    port for λ3 604.-   604—Output port for λ3.-   605—Optical path segment from dichroic beam splitter 602 to dichroic    beam splitter 607, with λ1 and λ2.-   606—Dichroic beam splitter, reflects λ1, passes λ2.-   607—Optical path segment from dichroic beam splitter 606 to output    port for λ1 608.-   608—Output port for λ1.-   609—Optical path segment from dichroic beam splitter 606 to output    port for λ2 610.-   610—Output port for λ2.-   611—Length of optical path segments 603 and 607, which equals W/2.-   612—Length of optical path 609, which also equals W/2.-   613—Length of optical path 605, which equals D, the distance between    dichroic beam splitters 602 and 606.-   701—Connector under inspection.-   702—Minor.-   703—Objective lens.-   704—Three-wavelength illumination source.-   705—Illumination beam splitter.-   706—Image lens, which provides auto focus function.-   707—Optical path to image sensor, which contains the image formed by    the current illumination wavelength.-   708—Image sensor used at all three wavelengths.-   709—Image plane 1, at focus range midpoint for λ1.-   710—Image plane 2, at focus range midpoint for λ2.-   711—Image plane 3, at focus range midpoint for a λ3.-   801—Image FOV for λ1, for sensor with 4:3 aspect ratio in portrait    orientation.-   802—Image FOV for λ2, for sensor with 4:3 aspect ratio in portrait    orientation.-   803—Image FOV for λ3, for sensor with 4:3 aspect ratio in portrait    orientation.-   804—Overlap of FOVs.-   805—Image and sensor horizontal dimension in pixels.-   806—Image and sensor vertical dimension in pixels.-   1001—Optical path segment from output port for λ3 604 to image    sensor for λ3 1002.-   1002—Image sensor for a λ3.-   1003—Image plane for a λ3.-   1004—Length of optical path 1001 is equal to D 613.-   1005—Optical path segment from output port for λ1 608 to image    sensor for λ1 1005.-   1006—Image sensor for λ1.-   1007—Image plane for λ1.-   1008—Length of optical path 1004 is equal to E1 410.-   1009—Optical path segment from output port for λ2 610 to image    sensor for λ2 1008.-   1010—Image sensor for λ2.-   1011—Image plane for λ2.-   1012—Length of optical path segment 1007 is equal to E2 411.-   1101—Beam splitter used to create two image planes.-   1102—Optical path to top image sensor 1103, which carries the image    created by the current wavelength.-   1103—Top image sensor, which captures top row images.-   1104—Image plane for top sensor, located at same distance as Image    Plane 2.-   1105—Optical path to the bottom image sensor, 1105, which also    carries the image created by the current wavelength.-   1106—Bottom image sensor, which captures bottom row images.-   1107—Image plane for bottom sensor.-   1201—Image FOV for λ1 and top sensor.-   1202—Image FOV for λ2 and top sensor.-   1203—Image FOV for λ3 and top sensor.-   1204—Image FOV for λ1 and bottom sensor.-   1205—Image FOV for λ2 and bottom sensor.-   1206—Image FOV for λ3 and bottom sensor.-   1207—Image FOV overlaps.-   1208—Image and sensor horizontal dimension in pixels.-   1209—Image and sensor vertical dimension in pixels.-   1401—Objective lens with optical FOV large enough to cover minimum    microscope FOV.-   1402—Single-wavelength illumination source.-   1403—Illumination beam splitter.-   1404—Image lens (auto focus).-   1405—Beam splitter used to create to the two image planes.-   1406—Optical path segment to left image sensor, carries full image.-   1407—Left image sensor.-   1408—Image plane for left image sensor.-   1409—Optical path segment to right image sensor, carries same image    as 1406.-   1410—Right image sensor.-   1411—Image plane for right image sensor.-   1501—Image FOV for left image sensor.-   1502—Image FOV for right image sensor.-   1503—FOV overlap.-   1504—Image and sensor horizontal dimension in pixels.-   1505—Image and sensor vertical dimension in pixels.-   1601—Right image sensor.-   1602—Left image sensor.-   1603—Image plane for left and right image sensors.-   1604—Middle image sensor.-   1605—Image plane for middle image sensor.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the features, components and/orsystems described herein. However, various changes, modifications, andequivalents of the features, components and/or systems described hereinwill be apparent to persons skilled in the art. Also, descriptions offunctions and constructions that are well known to persons skilled inthe art may have been omitted for increased clarity and conciseness. Thefeatures described herein may be embodied in different forms, and arenot to be construed as being limited to the examples described herein.Rather, the examples described herein have been provided so that thisdisclosure will be thorough and complete, and will convey the full scopeof the disclosure to persons skilled in the art.

In the following description of examples, reference is made to theaccompanying drawings which form a part hereof, and in which it is shownby way of illustration specific examples that can be practiced. It is tobe understood that other examples can be used and structural changes canbe made without departing from the scope of the disclosed examples.

Although examples of this disclosure have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of examples of this disclosure as defined bythe appended claims.

This description presents various exemplary embodiments of an imagingsystem that can be used to implement a multiple-fiber inspectionmicroscope. Such microscopes may include, or may be implemented as, aninspection probe or an inspection port, or both.

FIG. 3 shows the FOV shifter component included in one or moreembodiments, wherein the current FOV is determined by which wavelengthis active. The FOV-shifter component comprises three optical elements.The first is a dichroic beam splitter that reflects light at λ1 to andfrom the connector endface under inspection, but passes λ2 and λ3. Thesecond is a dichroic beam splitter that reflects λ2 and passes λ3. Thethird is a mirror used to reflect λ3. The difference between themidpoint of the image FOV at λ3 and midpoint of the image FOV at λ1 asE1. The difference between the midpoint of the image FOV at λ3 and themidpoint of the image FOV at λ2 is shown as E2. Thus, to equalizeoptical path lengths, the optical path length for λ2 needs to beextended by E2, while the optical path length for λ1 needs to beextended by E1.

The dichroic beam-splitters and mirror in the FOV shifter can bedesigned with a variety of different wavelength characteristics. Forexample, all could exhibit band-reflect characteristics at theirrespective wavelengths. Or, if λ1<λ2<λ3, then the dichroic beam-splitterat λ1 could be a longpass filter with an edge between λ1 and λ2, thedichroic beam-splitter at λ2 could be a longpass filter with an edgebetween λ2 and λ3, and the mirror used to reflect λ3 could be abroadband mirror. Moreover, dichroic beam-splitters or mirrors can beconstructed as dielectric mirrors deposited on the face of opticallyclear structures, which are then glued together and machined to createthe FOV shifter above and other components described later. However,persons skilled in the art will understand that other wavelengthcharacteristics, construction methods, and/or materials may be used toimplement these components as long as their functionality, as describedherein, is maintained.

FIG. 4 shows the optical path length equalizer component that is used inone or more of the embodiments of the imaging system to eliminate theoptical path length differences caused by the FOV shifter. Morespecifically, the embodiment shown in FIG. 4, which comprises fourdichroic beam splitters and two mirrors, is designed to provide equaloptical path lengths for the embodiments using a three-wavelengthillumination source and the three-wavelength FOV shifter shown in FIG.3.

To see this, first note that all wavelengths passing through the opticalpath length equalizer experience the same horizontal extension 515. Thennote that the vertical distance 516 between the two dichroicbeam-splitters 502 504 that reflect λ1 and λ2 and the two dichroicbeam-splitters 507 509 that reflect just λ2, equals ½ of the distancelabeled E2 in FIG. 3. Thus the path length equalizer eliminates thedifference between the optical path lengths at λ2 and λ3 caused by theFOV shifter. Similarly, the vertical distance 517 between the twodichroic beam-splitters 502 504 that reflect λ1 and λ2 and the twomirrors 512 514 used to reflect λ1 is ½ of E1. Thus the optical pathlength equalizer also eliminates the difference between the optical pathlengths at λ1 and λ3 caused by the FOV shifter.

FIG. 5 shows the wavelength-separator component used in one or moreembodiments of the imaging system. This embodiment, which includes twodichroic beam-splitters and three output ports, is designed to directeach of three received illumination wavelengths to the image sensorindicated in the figure.

FIG. 6 shows a three-wavelength, single-sensor embodiment that includesthe image FOV-shifter, an objective lens, a three-wavelengthillumination source and associated beam splitter, an image lens withauto-focus capability, for example a voltage-controlled liquid lens, anda single portrait-oriented image sensor. The image sensor is located atthe midpoint of the focal range for λ2. Thus the system retains fullautofocus range at λ2. However, autofocus range is reduced by thedistance E2 at the other two wavelengths.

FIG. 7 shows how the FOVs of the images captured by thethree-wavelength, single-sensor embodiment of FIG. 6 would cover theminimum microscope FOV, assuming the sensor is portrait-oriented and hasa 4:3 aspect ratio.

FIG. 8 shows the embodiment of FIG. 6 modified by adding the opticalpath length equalizer of FIG. 4 and by moving the image sensor to thelocation that is at the midpoint of the autofocus range for allthree-wavelengths. As a result, this embodiment enjoys full autofocusrange at all three illumination wavelengths.

FIG. 9 shows the embodiment of FIG. 6 modified by adding a wavelengthseparator (600) and two additional portrait-oriented image sensors. Inaddition, all three image sensors are positioned relative to thewavelength separator to create equal optical path lengths at all threeillumination wavelengths. Specifically, the distance from the wavelengthseparator to the sensors used at λ1, λ2, and λ3 are E1, E2, and Drespectively. As described earlier, in embodiments that use thethree-wavelength FOV-shifter shown in FIG. 3, E1 and E2, respectively,are the path length extensions needed to make the optical path lengthsat λ1 and λ2 equal to the optical path length at λ3. Another advantageof the embodiment shown in FIG. 9 is that it allows the imaging systemto operate with all illumination wavelengths active at the same time,which means that all three images can be captured simultaneously ratherthan sequentially, which can reduce the time required to capture allimages.

The embodiment illustrated by FIG. 10 is the embodiment of FIG. 6modified by replacing a single portrait-oriented sensor with one beamsplitter and two landscape-oriented sensors in order to either create alarger microscope FOV or to increase image resolution, assuming the sametype sensors are used in both embodiments. The two sensors are locatedon different image planes, with the Top Sensor disposed to captureimages of the top half of the minimum microscope FOV, and the BottomSensor disposed to capture images of the bottom half of the microscopeFOV.

FIG. 11 shows how the six images created by the three-wavelength,two-sensor embodiment of FIG. 10 would cover the minimum microscope FOV,assuming both sensors included in the embodiment are landscape-orientedand have a 4:3 aspect ratio. Note that the top row of three images iscaptured by “Top” sensor, while the bottom row of three images iscaptured by the “Bottom” sensor.

FIG. 12 shows the embodiment of FIG. 10 modified by adding the opticalpath length equalizer of FIG. 4 and by moving the two image sensors tolocations that are at the midpoint of the autofocus range for all threewavelengths. As a result, this embodiment enjoys full autofocus range atall three illumination wavelengths.

FIG. 13 shows a single-wavelength, two-sensor embodiment of the imagingsystem, wherein two-sensors are located on two different image planes,and wherein both image planes are located at the midpoint of theautofocus range of the optical system. It should be noted that theillumination source can operate at more than one wavelength, for exampleto provide improved detect detection. However, this is not required forFOV shifting as it is in other embodiments.

FIG. 14 shows how the FOVs of the two images captured by the embodimentof FIG. 13 would cover the minimum microscope FOV, assuming both sensorshave a landscape orientation and a 4:3 aspect ratio.

FIG. 15 shows a single-wavelength, three-sensor embodiment, wherein thethree sensors are located on two different image planes, and whereinboth image planes are located at the midpoint of the autofocus range ofthe optical system. It should be noted that the illumination source canoperate at more than one wavelength, for example to provide improveddetect detection. However, this is not required for FOV shifting as itis in other embodiments.

FIG. 16 shows how the FOVs of the images captured by the embodiment ofFIG. 15 would cover the minimum microscope FOV, assuming all threesensors have a portrait orientation and a 4:3 aspect ratio.

1. A fiber optic connector imaging system with autofocus capability forinspecting multifiber connectors that comprises: a housing structure tocontain the optical and electro-optical components of the imagingsystem; a mating structure to maintain the endface of the connectorunder inspection within the autofocus range of the imaging system duringthe image capture process; an illumination source that can operate atany one of two or more wavelengths at any given time; an FOV-shiftercomprising one or more dichroic mirrors and an additional mirror whichcan be dichroic or broadband; an autofocus optical system that comprisesone or more fixed or autofocus lenses; and a single image sensor;wherein the imaging system can capture an image of a different sectionof the endface of the multifiber connector under inspection, dependingon which illumination wavelength is active, wherein the captured imagesas a group will have sufficient resolution and a sufficient FOV to beused to perform automatic or manual pass-fail analysis of the endfacesof all fibers terminated by the multifiber connector under inspection.2. The imaging system according to claim 1, wherein the single imagesensor is replaced by an image beam splitter and two or more imagesensors located on either of the two image planes created by the beamsplitter, in order to increase the resolution of the captured images orallow the use of image sensors with lower pixel counts.
 3. The imagingsystem according to claim 1, wherein an optical path length equalizercomponent is added to allow the image sensor to be located at theautofocus range midpoint of all illumination wavelengths and thus retainthe full autofocus range of the optical system at all illuminationwavelengths.
 4. The imaging system according to claim 2, wherein anoptical path length equalizer component is added to allow all of theimage sensors to be located at the autofocus range midpoint of allillumination wavelengths in order to retain the full autofocus range ofthe optical system at all illumination wavelengths.
 5. The imagingsystem according to claim 1 wherein the single image sensor is replaceby a wavelength separator and two or more image sensors, wherein theimage separator directs the current image to a different sensordepending on which illumination wavelength is active, wherein each ofthe image sensors is positioned relative to the wavelength separator inorder to achieve the same optical path length at all illuminationwavelengths and thus retain the full autofocus range of the opticalsystem at all illumination wavelengths.
 6. The imaging system accordingto claim 5, wherein all illumination wavelengths are active at the sametime to allow images to be captured at all wavelengths simultaneously.7. A fiber optic connector imaging system with autofocus capability forinspecting multifiber connectors that comprises: a housing structure tocontain the optical and electro-optical components of the imagingsystem; a mating structure to maintain the endface of the connectorunder inspection within the autofocus range of the imaging system duringthe image capture process; a single-wavelength illumination source andassociated beam splitter; an autofocus optical system that comprises oneor more fixed or autofocus lenses; an image beam splitter and two ormore image sensors located on either of the two image planes created bythe image beam splitter; wherein each image sensor can capture an imageof a different section of the endface of the multifiber connector underinspection, wherein these captured images as a group will havesufficient resolution and a sufficient FOV to be used to performautomatic or manual pass-fail analysis of the endfaces of all fibersterminated by the multifiber connector under inspection.